Vehicle wheel end assembly

ABSTRACT

A method of making a vehicle wheel end assembly (10) is adaptable for use with an on-board central tire inflation system. The assembly provides a passage for the routing of air between the on-board system and the vehicle tire. The assembly comprises a stationary spindle (12) and a rotational hub (14) mounted thereon. The hub is supported for rotation by first and second axially spaced bearing sets (16, 18), each having an inner race (20, 26) and an outer race (22, 28) associated with the spindle and hub, respectively. The inner race of the inboard bearing set (18) is formed with an axial air passage (46) which communicates with an internal chamber (36) in the hub to form a portion of the air passage between the tire and on-board system. In another feature, rotary seals (60, 62) are seated in opposed faces of the bearing sets and include sealing lips (72) which have a sealed contact with the upper surface of the inner bearing races. An inboard spindle collar (100) may also be employed to facilitate the continuation of the air passage (98) in the bearing race (90) to the on-board system.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 08/088,229 filed Jul.6 1993, now U.S. Pat. No. 5,354,391, which is a continuation of U.S.Ser. No. 07/750,436, filed Aug. 20, 1991 now U.S. Pat. No. 5,236,028;which is a division of 07/143,022, filed Jan. 12, 1988, now abandoned;which is a continuation of 06/752,576, filed Jul. 8, 1985, now U.S. Pat.No. 4,730,656.

TECHNICAL FIELD

This invention relates to central tire inflation systems, and, moreparticularly, to a wheel end assembly adapted for use with such asystem.

BACKGROUND ART

The present invention presents an alternative design to the vehiclewheel end assembly disclosed in application Ser. No. 712,420, filed Mar.18, 1985, now U.S. Pat. No. 4,733,707 and assigned to the assignee ofthe present invention.

In the co-pending application it was recognized that one of theimportant design considerations inherent in a central tire inflationsystem is the need for a reliable seal in the wheel assembly betweenrotating and non-rotating members. This design consideration isaddressed by the present invention in a manner which requires minimalnecessary modifications of the major components, i.e. spindle and hub,of the wheel end.

DISCLOSURE OF THE INVENTION

The present invention provides a wheel end assembly for a central tireinflation system which features modification of the wheel bearings toachieve a reliable sealed air passage between the rotational andnon-rotational members of the assembly.

In broad terms the wheel end assembly of the present invention comprisesa spindle or axle housing which is non-rotational and attached to thevehicle chassis. A hub is mounted concentrically on the spindle forrotation thereon. The hub is associated with a first air path portion,and as shown in the preferred embodiment illustrated in the drawing, isformed with an internal chamber which represents a portion of theoverall air passage between the onboard inflation system and therespective pneumatic tire mounted on the wheel.

The hub is supported for rotation on the spindle by first and secondaxially spaced bearing sets. Each bearing set has a non-rotational innerrace associated with the spindle and a rotational outer race associatedwith the hub. The inner race of the inboard bearing set is formed withan axial air passage which communicates with the internal chamber in thehub to provide an inboard continuation or associated second air pathportion of the overall air passage.

In another feature of the invention, the rotary sealing between therotational hub and the non-rotational spindle is accomplished by a pairof annular rotary seals mounted on the respective inboard and outboardbearing sets. More specifically, each annular seal includes a flangeportion which seats in a notch formed in the face of the outer race. Anintegral lip extends radially inward and into sealing contact with theupper surface of the inner race. The seal flanges are secured in theirnotched seats by cooperation of the hub.

In an alternate embodiment of the invention, an inboard collar may bemounted on the spindle to facilitate coupling of the air passage formedin the inner race of the inboard bearing set with the on-board system.

Other features and advantages of the invention will become apparent inconnection with the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side sectional view of the relevant portion of a vehiclewheel end assembly in accordance with the present invention;

FIG. 2 is an enlarged view of a portion of the wheel end assembly ofFIG. 1 illustrating the sealed air passage between the rotational andnon-rotational members in greater detail;

FIG. 3 is an end view of a sleeve mounted concentrically on the spindleto maintain spacing of the hub during installation and removal;

FIG. 4 is a side elevation view of the sleeve taken along line 4--4 ofFIG. 3; and

FIG. 5 is an enlarged sectional view of an alternative embodiment of thewheel end assembly featuring an inboard collar which mounts on thespindle and interconnects the air passage in the inner bearing race toair lines which extend to the on-board system.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 illustrates the portion of a vehicle wheel end assembly 10relevant to an understanding of the present invention. The assembly 10is suited for use with an on-board automated system for controlling tirepressurization. A wheel end assembly of similar function is disclosed inco-pending application Ser. No. 712,420, filed Mar. 18, 1985 now U.S.Pat. No. 4,733,707 and assigned to the assignee of the presentinvention.

The wheel end assembly 10 includes a spindle or axle housing 12 which ismounted in fixed relation to the vehicle chassis. A hub 14 is mountedfor rotation on the spindle 12. The hub 14 is driven in a conventionalmanner by an axle shaft and drive flange (not shown but understood inthe art).

The hub 14 is supported for rotation on the spindle 12 by an outboardbearing set 16 and an inboard bearing set 18. The bearing set 16includes an inner race 20 mounted on the spindle 12. An outer race 22 ismounted on the hub 14 and is co-rotational with the hub. Arepresentative tapered roller bearing 24 is disposed between the innerrace 20 and the outer race 22.

The bearing set 18 similarly includes an inner race 26 associated withthe spindle 12 and an outer race 28 which is co-rotational with the hub14. A representative tapered roller bearing is shown at 30.

The inner races 20 and 26 each have formed in them grooves to receiverespective O-rings 31 and 33 to provide a fluid seal between theunderside of the race and the spindle 12.

The hub 14 is formed with an internal air chamber which represents aportion of an overall air path between the on-board automated system andthe respective tire carried by the vehicle wheel end assembly. A sleeve38 is disposed in a major portion of the volume between the hub cavity36 and the outer surface of the spindle 12. The function of the sleeve38 is as a spacer means to minimize abrasion of the components adjacentthe spindle 12 against the outboard spindle threads 15 when the hub 14is fitted onto or removed from the spindle. The sleeve 38 has anoninterfering relation to the passage of air within the volume itoccupies.

With reference to FIGS. 3 and 4, the sleeve 38 is shown in greaterdetail. It can be seen that the sleeve has a substantially cylindricalshape with radial surface undulations 40. The opposite ends of thesleeve 38 are formed with scallops 41 to permit radial flow of air withminimal obstruction.

Again with reference to FIG. 1, the environment of the bearing set 18 issealed from foreign material by a dirt slinger 32 which includes a pairof fingers which bear against a ring 34 mounted concentrically on theinner race 26.

A feature of the present invention is the manner in which pressurizedair is routed between the tire carried by the wheel end assembly 10 andthe on-board system. In traversing this route in an outboard to inboardorder, the air passage begins with an aperture 43 formed in an integralradial segment of the hub 14. The aperture 43 may be fitted with ahollow stud 42 or the like to facilitate connection to a conventionalair line (not shown) outboard of the assembly 10.

A tube 47 is connected between the hollow stud 42 and a fitting 44. Thefitting 44 has a threaded engagement with a tapped hole 45 formed in thehub 14.

The air path is continuous through the internal chamber 36 in the hub 14to a passage 46 formed in the inner race 26 of the inboard bearing set18. The air passage 46 is ported generally inboard of the hub 14 andconnected to an adapter 48. The adapter 48 is in turn connected to oneend of a tube 54 through a conventional fitting 50. The other end of thetube 54 is connected to one side of an elbow 56. The other side of theelbow is connected to a fitting 58 mounted on a chassis member 64. Fromthis point the air can be routed to the on-board system in aconventional manner.

The air passage just described is sealed in the environment of the hubchamber 36 by a pair of rotary seals indicated generally at 60 and 62.The seal 60 is mounted in fixed relation to the outer bearing race 22 incooperation with the hub 14 and has a sealed contact with an extension66 of the inner race 20.

Similarly, the rotary seal 62 is mounted in fixed relation to the outerrace 28 bearing sets 18 with the cooperation of the hub 14, and has asealed contact with an extension 68 of the inner race 26.

FIG. 2 illustrates in greater detail the localized area of the in-boardbearing set 18.

The inner, non-rotational race 26 is shown mounted on the spindle 12 andsealed there against by the O-ring 33.

The rotary seal assembly 62 comprises several constituents described asfollows. A generally radially extending flange portion 70 is mated witha reinforcing segment 74 and mounted in a notch 65 formed in theinternal face of the outer race 28. The flange 70 and reinforcing member74 are held in fixed position relative to the outer race 28 with thecooperation of a dependent shoulder 76 of the hub 14. As shown in FIG.2, this cooperation locates and seats the rotary seal means in a mannerwhich seals the outer race 28 to the hub 14.

The radial flange 70 is connected to a lip segment 72 formed of lowfriction material which contacts the extension 68 of the inner race 26.A garter spring 78 provides a radial inward force to hold the lip 72into sealed contact with the extension 68 of the inner race 26. The airpassage 46 through the inner race 26 thereby communicates with the hubchamber 36 and is sealed at the inboard end by the action of the rotaryseal assembly 62.

The air passage 46 is ported at its inboard end through a threadedfitting 80 which couples to the adapter 48. As previously described inreference to FIG. 1, the adapter receives a fitting 50 which is in turnconnected to a tube 54. As shown in FIGS. 1 and 2, air passage 46 isformed at least in part by a peripheral recess in the inner race.

FIG. 5 is an alternative embodiment of a vehicle wheel end assembly,indicated generally at 10', of the present invention. In description ofFIG. 5, like reference numerals will be used for members common to theembodiments of FIGS. 1 and 5.

The vehicle wheel end assembly 10' similarly includes a spindle 12 and ahub 14 mounted for rotation on the spindle. The hub 14 is supported forrotation at the inboard end by a bearing set which includes an innerrace 90 associated with the spindle, and an outer race 94 which isco-rotational with the hub 14. A roller bearing 92 is disposed betweenthe inner race 90 and the outer race 94.

An annular dust seal 96 having a channel-shaped cross section is pressfit into the radial gap between the inner race 90 and the outer race 94rearward of the roller bearing 92.

The inner race 90 is formed with an axially extending air passage 98 tocommunicate the chamber 36 between the spindle 12 and the hub 14 with acollar, indicated generally at 100. As shown in FIG. 5, the air passage98 is formed by a peripheral recess in the inner race 90. The collar 100is positioned inboard of the bearing set and mounted concentrically onthe spindle.

The collar 100 includes an annular body 102 and an integral flange 104which extends radially inward from the body.

The annular body 102 is seated on a step 106 on the spindle 12. Anannular groove 103 is formed in the inner radial surface of the body 102and seats an O-ring 105 to seal the collar 100 against the spindle 12.

The inward radial flange 104 includes a lip 110 which cooperates with anotch 111 formed in the inboard axial face of the race 90 to seat andseal another O-ring 112.

The collar 100 communicates with the axial extending passage 98 in theinner race 90 through a radial bore 108. The outer opening of the bore108 is closed by a plug 115. An axial bore 114 continues the air pathwith the radial bore 108. The inboard end of the axial bore 114 isclosed by a plug 116. A second radial bore 118 continues the air path toan air line which extends to the on-board system. The second radial bore118 is threaded to receive the fitting 50. As previously described inconnection with FIG. 2, the fitting 50 connects through tube 54, elbow56 and fitting 58 to continue the air path toward the on-board automatedsystem.

Although the invention has been shown and described in specificembodiments it is to be understood that the modifications to thedisclosed designs may be made without departing from the scope of thefollowing claims.

We claim:
 1. A method for providing inflation air flow passageways in avehicle end assembly adapted for use with an automated system forcontrolling tire inflation, wherein the wheel end assembly has a spindleand a hub which is mounted for rotation on the spindle and having an airpath for fluid flow communication between the automated system and therespective tire, and wherein the wheel assembly receives bearing meansfor rotatably supporting the hub on the spindle in operative positionbetween the spindle and the hub, the method comprising the steps of:(a)installing a bearing set with an inflation air flow passagewaytherethrough; and (b) sealing the bearing set with respect to the huband to the spindle.
 2. The method according to claim 1 wherein thebearing set includes an inner race and an outer race and said installingstep includes the step of forming an air passageway through one of theraces.
 3. The method according to claim 1 wherein the bearing setincludes inner and outer races and wherein the step of sealing includesthe step of sealing the inner and outer races respectively to thespindle and to the hub.
 4. The method according to claim 3 and furthercomprising installing a collar on the spindle having an air passageextending between a first port, which communicates with the air path,and a second port which communicates with the automated system.
 5. Themethod according to claim 4 wherein the step of sealing the inner raceto the spindle comprises the steps of sealing said inner race to saidcollar and sealing said collar to said spindle.
 6. The method accordingto claim 3 and further including the step of providing a rotary sealbetween the inner and outer races.
 7. The invention as defined in claim6 wherein said step of providing a rotary seal comprises locating andseating a seal ring flange between a race and one of the spindle and thehub.
 8. The invention as defined in claim 6 wherein said step ofproviding a rotary seal comprises forcing a low friction lip in sealedcontact with one of the races.
 9. The method according to claim 1wherein said step of installing includes installing first and secondbearing sets and providing said air passageway through only one of saidfirst and second bearing set.
 10. The method according to claim 1 andincluding the step of forming an air passageway through said bearing setprior to said step of installing.
 11. A method for providing airpassageways in a vehicle end assembly adapted for use with an automatedsystem for controlling tire pressurization, wherein the wheel endassembly has a spindle and a hub which is mounted for rotation on thespindle and having an air path for fluid communication between theautomated system and the respective tire, and wherein the wheel assemblyreceives baring means for rotatable supporting the hub on the spindle inoperative position between the spindle and the hub, the methodcomprising the steps of:(a) installing a bearing set with an airpassageway therethrough; and (b) sealing the bearing set with respect tothe hub and to the spindle; andwherein the bearing set includes an innerrace and an outer race and said installing step includes the step offorming an air passageway through one of the races.
 12. The methodaccording to claim 11 wherein said installing step further comprisesproviding a peripheral recess in said one race.
 13. The method accordingto claim 11 wherein the bearing set includes inner and outer races andwherein the step of sealing includes the step of sealing the inner andouter races respectively to the spindle and to the hub.
 14. The methodaccording to claim 13 and further including the step of providing arotary seal between the inner and outer races.